CN114326320B - Control method, device, equipment and storage medium for stepper lithography - Google Patents

Abstract

Embodiments of the present invention disclose a control method, device, equipment and storage medium for stepper lithography. The control method of the stepper lithography includes: obtaining the actual moving distance of the lithography equipment after one step; determining the step error of one step based on the actual moving distance and the preset step length; and performing the step error on the spot image based on the step error. Adjust to compensate for exposure image errors caused by step errors. This solution adjusts the specific position of the spot image projection, so as to ensure the accuracy of the spot image position, so that the exposed image will not produce gaps or overlapping parts on the parts to be lithographed, thereby achieving continuity of the exposed image and improving Exposure image accuracy.

Description

Control method, device, equipment and storage medium for stepper lithography

Technical field

Embodiments of the present invention relate to the field of photolithography technology, and in particular, to a control method, device, equipment and storage medium for stepper photolithography.

Background technique

Stepping motion is to move the light spot from one preset position to another. It usually requires the light spot to move accurately to the preset position. The existing stepper lithography equipment works as follows: using a grating ruler to read the position of the motion system. When the grating ruler reads that the motion system is close to the preset position, the motor of the motion system is controlled to decelerate and brake, and the movement is stopped when the motor stops. The system stops at the preset position. However, due to the accuracy error Δx of the motion system, the position where the motion system stops will be within the range of ±Δx from the preset position. This will lead to a step deviation in the exposure image. If there are too many steps, a gap will be generated between the two preset positions. If there are too few steps, there will be an overlap between the two positions. It is impossible to ensure that the light spot before and after the step is on the target. Continuity of surface projected images.

Contents of the invention

Embodiments of the present invention provide a stepper lithography control method, device, equipment and storage medium to achieve continuity of exposure images and improve the accuracy of exposure images.

In a first aspect, an embodiment of the present invention provides a control method for stepper lithography, including:

Obtain the actual moving distance of the lithography equipment after one step;

Determine the step error of a step based on the actual moving distance and the preset step length;

The spot image is adjusted based on the step error to compensate for the exposure image error caused by the step error.

Optionally, adjusting the spot image based on the step error includes:

The step error means that when a step is greater than the preset step length, the exposure image is increased by the width of the step error in the step direction, and the exposure image is increased by the step error distance in the reverse direction of the step. Compensates for exposure image errors caused by step errors.

Optionally, adjusting the spot image based on the step error also includes:

The step error means that when a step is smaller than the preset step length, the exposure image is reduced by the width of the step error in the step reverse direction, and the exposure image is displaced in the step direction by the distance of the step error. Compensates for exposure image errors caused by step errors.

Optionally, obtain the actual moving distance of the lithography equipment after one step, including:

Control the lithography equipment to move in the step direction according to the preset step length;

The actual movement distance of the lithography equipment is determined based on the movement of the positioning device.

Optionally, before obtaining the actual moving distance of the lithography equipment after one step, include:

According to the movement accuracy of the lithography equipment, set the parameters of the spot image projected by the lithography equipment; and or divide the image to be exposed according to the parameters of the spot image.

Optionally, the parameters of the spot image projected by the lithography equipment include: the projection length of the spot image and the projection width of the spot image;

Among them, the projection length of the spot image is less than or equal to the maximum projection length of the lithography equipment minus 2 times the movement accuracy of the lithography equipment; the projection width of the spot image is equal to the maximum projection width of the lithography equipment.

Optionally, divide the image to be exposed according to the parameters of the spot image, including:

The exposure image is divided into multiple strip images based on the projection length of the spot image and the movement accuracy of the lithography equipment. Each strip image includes a projection area in the middle and compensation areas on both sides;

The width of the projection area is equal to the projection length of the spot image, and the width of the compensation area is greater than the movement accuracy of the lithography equipment.

Optionally, the projection areas of adjacent strips do not overlap, the compensation areas of adjacent strips overlap with the projection areas of adjacent strips, and the total length of adjacent compensation areas is greater than or equal to 2 times the movement of the lithography equipment. Precision, less than or equal to 2 times the projection length of the spot image.

In a second aspect, embodiments of the present invention also provide a control device for stepper lithography, including:

A position determination device used to obtain the actual moving distance of the lithography equipment after one step;

The error determination device determines the step error of a step based on the actual moving distance and the preset step length;

The spot adjustment device adjusts the spot image based on the step error to compensate for the exposure image error caused by the step error.

In a third aspect, embodiments of the present invention also provide a control device for stepper lithography. The control device for stepper lithography includes:

one or more processors;

When one or more programs are executed by one or more processors, the one or more processors implement any of the above stepper lithography control methods.

In a fourth aspect, embodiments of the present invention also provide a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, any one of the above stepper lithography control methods is implemented.

The technical solution of this embodiment is to first obtain the actual moving distance of the lithography equipment after one step, then determine the step error of one step based on the actual moving distance and the preset step length, and finally calculate the spot image based on the step error. Adjustment is made to compensate for the exposure image error caused by the step error, thereby ensuring the accuracy of the spot image projection position, thereby achieving no gaps or overlapping parts of the exposed image on the part to be lithographed, and achieving continuity of the exposure image. Improve the accuracy of exposed images.

Description of the drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief introduction will be made below to the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description Although these are some specific embodiments of the present invention, those skilled in the art can expand and extend the basic concepts of the device structure, driving method and manufacturing method according to the various embodiments of the present invention. Other structures and drawings are undoubtedly within the scope of the claims of the present invention.

Figure 1 is a schematic flow chart of a stepper lithography control method provided by an embodiment of the present invention;

Figure 2 is an exposure image produced by a lithography equipment provided by an embodiment of the present invention under error-free step lithography;

Figure 3 is an exposure image produced by a lithography equipment provided by an embodiment of the present invention under the first type of step error;

Figure 4 is an exposure image produced by a lithography equipment provided by an embodiment of the present invention under the second type of step error;

Figure 5 is an adjusted exposure image of Figure 4 provided by an embodiment of the present invention;

Figure 6 is an adjusted exposure image of Figure 3 provided by an embodiment of the present invention;

Figure 7 is a schematic flow chart of another stepper lithography control method provided by an embodiment of the present invention;

Figure 8 is a schematic structural diagram of a micromirror array or laser array provided by an embodiment of the present invention;

Figure 9 is a schematic structural diagram of a light spot image provided by an embodiment of the present invention;

Figure 10 is a schematic structural diagram of a strip image segmentation provided by an embodiment of the present invention;

Figure 11 is a scanning lithography equipment provided by an embodiment of the present invention;

Figure 12 is a control device for stepper lithography provided by an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

Figure 1 is a schematic flowchart of a stepper lithography control method provided by an embodiment of the present invention. This embodiment can be applied to situations where stepper lithography is required. The method includes:

S110. Obtain the actual moving distance of the lithography equipment after one step.

Among them, the lithography equipment realizes photolithography positioning at different positions of the parts to be lithographed through step-by-step movement. The accuracy of the actual moving distance of the lithography equipment after each step is consistent with the continuity of the exposed image on the parts to be lithographed. closely related to accuracy. Therefore, in order to obtain the accuracy of the actual movement distance of the lithography equipment after each step, it is necessary to obtain the actual movement distance of the lithography equipment after one step. Specifically, the actual moving distance of the lithography equipment after one step needs to be read in real time through the positioning device on the lithography equipment to ensure the accuracy of obtaining the actual moving distance of the lithography equipment after one step. For example, the positioning device on the lithography equipment is a grating ruler and a reading head. The reading head can obtain the actual moving distance of the lithography equipment after one step based on the reading of the grating ruler.

S120. Determine the step error of one step according to the actual moving distance and the preset step length.

Among them, the lithography equipment moves step by step according to the preset step length. Since the movement of the lithography equipment is driven by the operation of the motor, the step movement of the lithography equipment cannot be guaranteed when it moves according to the preset step length. The accuracy of the distance causes the actual moving distance of the lithography equipment after one step to be greater or less than the preset step length. In order to ensure the continuity and accuracy of the exposed image on the part to be lithographed, the step error of one step needs to be determined based on the actual movement distance and the preset step length, so that the exposure can be adjusted according to the step error of the lithography equipment. The position of the image, thereby achieving continuity and accuracy of the exposed image.

S130. Adjust the spot image based on the step error to compensate for the exposure image error caused by the step error.

Among them, the spot image is generated by lithography equipment. The lithography equipment can use digital light processing technology (Digital Light Processing, DLP) or laser close-packing technology to generate a specific spot image. Specifically, if the lithography equipment adopts digital light processing technology, a digital micromirror device (DMD) can be used to generate a spot image of a specific shape. If the lithography equipment adopts laser close-packing technology, precisely arranged lasers can be used to produce spot images of specific shapes. In summary, it can be seen that the spot image will move with the movement of the lithography equipment. In addition, the specific position of the spot image can also be adjusted and moved through digital micromirror devices or precisely arranged lasers. The adjustment of the spot image based on the step error is a micro-adjustment of the position of the spot image through a digital micromirror device or a precisely arranged laser.

Specifically, the step error includes two types of step errors. The first type of step error is the step error generated when the actual moving distance of the lithography equipment after one step is less than the preset step length. The second type of step error is the step error caused by the actual movement distance of the lithography equipment after one step being greater than the preset step length. Exemplarily, Figure 2 is an exposure image produced by a lithography equipment provided by an embodiment of the present invention under error-free step lithography. Figure 3 is a first type of lithography equipment provided by an embodiment of the present invention. The exposure image generated under the second type of step error. FIG. 4 is an exposure image generated under the second type of step error by a lithography equipment provided by an embodiment of the present invention. Comparing Figure 2 and Figure 3, it can be seen that the lithography equipment that generates the first type of step error has not moved to the target position. At this time, the actual position of the lithography equipment after stepping in the stepping direction is relatively behind. At this time, it is necessary to pass Digital micromirror devices or precisely arranged lasers move the spot image in the step direction to compensate for the exposure image error caused by the step error. Comparing Figure 2 and Figure 4, it can be seen that the lithography equipment that generates the second type of stepping error has not moved to the target position. At this time, the actual position of the stepping equipment after stepping in the stepping direction is relatively advanced. Therefore, it is necessary to pass The second type of step error occurs when a digital micromirror device or a precisely arranged laser moves the spot image in the opposite direction of the step to compensate for the exposure image error caused by the step error.

The technical solution of this embodiment is to first obtain the actual moving distance of the lithography equipment after one step, then determine the step error of one step based on the actual moving distance and the preset step length, and finally calculate the spot image based on the step error. Adjustment is made to compensate for the exposure image error caused by the step error, thereby ensuring the accuracy of the spot image projection position, thereby achieving no gaps or overlapping parts of the exposed image on the part to be lithographed, and achieving continuity of the exposure image. Improve the accuracy of exposed images.

Specifically, adjusting the spot image based on the step error includes: the step error indicates that when a step is greater than the preset step length, the exposure image is increased by the width of the step error in the step direction, and the step direction is reversed. The distance to the step error of the exposure image after the displacement is increased to compensate for the exposure image error caused by the step error.

Among them, before adjusting the spot image based on the step error, the type of the step error needs to be judged. If the step error indicates that one step of the lithography equipment is greater than the preset step length, the lithography equipment steps in the step direction. The actual position is relatively advanced, so the spot image needs to be adjusted and moved through digital micromirror devices or precisely arranged lasers. Specifically, it is first necessary to increase the exposure image by the width of the step error in the step direction to avoid the loss of image information of the step error width after subsequent movement of the spot image, and to compensate for the loss of the exposure image caused by the step error. Then the step error distance of the increased exposure image is shifted in the reverse direction, so that the exposure image after the increase in displacement is seamlessly connected to the previous exposure image, achieving continuity of the exposure image and improving the accuracy of the exposure image. . For example, FIG. 5 is an adjusted exposure image of FIG. 4 provided by an embodiment of the present invention.

Specifically, adjusting the spot image based on the step error also includes: when the step error indicates that a step is smaller than the preset step length, the exposure image is reduced by the width of the step error in the step reverse direction, and the step error is adjusted to the step error. The distance of the exposure image step error after the forward direction displacement is reduced to compensate for the exposure image error caused by the step error.

Among them, if the step error indicates that one step is smaller than the preset step length, the actual position of the stepping device after stepping in the step direction is relatively lagging behind. Therefore, it is necessary to use a digital micromirror device or a precisely arranged laser to adjust the light spot. The image is adjusted and moved. Specifically, it is first necessary to reduce the exposure image by the width of the step error in the step reverse direction to avoid the overlap of image information of the step error width after subsequent movement of the spot image, and to remove the redundant exposure image generated by the step error. . The reduced exposure image is then displaced in the step direction by the distance of the step error, so that the reduced exposure image is seamlessly connected to the previous exposure image, achieving continuity of the exposure image and improving the accuracy of the exposure image. For example, FIG. 6 is an adjusted exposure image of FIG. 3 provided by an embodiment of the present invention.

Figure 7 is a schematic flow chart of another stepper lithography control method provided by an embodiment of the present invention. As shown in Figure 7, the specific steps of the method include:

S210. Set the parameters of the spot image projected by the lithography equipment according to the movement accuracy of the lithography equipment; and or divide the image to be exposed according to the parameters of the spot image.

Among them, the movement accuracy of the lithography equipment is the maximum error generated when the lithography equipment moves stepwise according to the preset step length. According to the maximum error generated during the step movement of the lithography equipment, set the specific parameters of the spot image projected by the lithography equipment. The spot image will move with the movement of the lithography equipment. Therefore, the error of the step movement of the spot image as the lithography equipment moves is less than or equal to the movement accuracy of the lithography equipment.

Specifically, the parameters of the spot image projected by the lithography equipment include: the projection length of the spot image and the projection width of the spot image; wherein the projection length of the spot image is less than or equal to the maximum projection length of the lithography equipment minus 2 times the lithography equipment Movement accuracy; the projection width of the spot image is equal to the maximum projection width of the lithography equipment.

For example, if the movement accuracy θ of the lithography equipment is ±40um, the maximum projection length of the lithography equipment is 28mm, the projection length of the spot image is T≤28mm-2*40um, the projection width of the spot image is equal to the maximum projection length of the lithography equipment. Projection width. According to the movement accuracy of the lithography equipment, the projection length of the spot image is reduced, and the position of the spot image can be adjusted through a digital micromirror device or a precisely arranged laser. Specifically, a part of the micromirror array or the laser array is always closed, so that the spot image can be moved by a distance of the step error by adjusting the opening and closing parts of the micromirror array or the laser array to compensate for the step error. The resulting exposure image error.

Exemplarily, Figure 8 is a schematic structural diagram of a micromirror array or laser array provided by an embodiment of the present invention, and Figure 9 is a schematic structural diagram of a spot image provided by an embodiment of the present invention, as shown in Figures 8 and 9 , the length of the micromirror array or laser array is X+2θ, the width of the micromirror array or laser array is Y, the length of the spot image 010 is X, and the width of the spot image 010 is Y.

Optionally, dividing the image to be exposed according to the parameters of the spot image includes: dividing the exposure image into multiple strip images according to the projection length of the spot image and the movement accuracy of the lithography equipment, each strip image including a The projection area and the compensation areas on both sides; the width of the projection area is equal to the projection length of the spot image, and the width of the compensation area is greater than the movement accuracy of the lithography equipment.

Among them, the width of the projection area is set according to the projection length of the spot image, and the width of the compensation area is set according to the movement accuracy of the lithography equipment. Specifically, the width of the projection area is equal to the projection length of the spot image, and the width of the compensation area is greater than the movement accuracy of the lithography equipment.

Exemplarily, Figure 10 is a schematic structural diagram of strip image segmentation provided by an embodiment of the present invention. As shown in Figure 10, the exposure image is divided into multiple strips according to the projection length of the spot image and the movement accuracy of the lithography equipment. Strip images, such as strip image 510, strip image 520, and strip image 530. Each strip image includes a projection area in the middle and compensation areas on both sides. For example, the strip image 510 includes a projection area 511 in the middle (rectangular area framed by solid lines) and compensation areas 512 (shaded areas) on both sides. ; The strip image 520 includes a projection area 521 in the middle (rectangular area framed by solid lines) and compensation areas 522 (shaded areas) on both sides; the strip image 530 includes a projection area 531 (rectangular area framed by solid lines) in the middle. rectangular area) and compensation areas 532 on both sides (shaded areas).

Optionally, the projection areas of adjacent strips do not overlap, the compensation areas of adjacent strips overlap with the projection areas of adjacent strips, and the total length of adjacent compensation areas is greater than or equal to 2 times the movement of the lithography equipment. Precision, less than or equal to 2 times the projection length of the spot image.

For example, continuing to refer to FIG. 10 , the projection area 511 of the strip image 510 and the projection area 521 of the adjacent strip image 520 do not overlap, and the compensation area 512 of the strip image 510 does not overlap with the projection area of the adjacent strip image 520 . The areas 521 overlap, and the total length of the adjacent compensation area 512 and the compensation area 522 is greater than or equal to 2 times the movement accuracy of the lithography equipment, and is less than or equal to 2 times the projection length of the spot image.

S220. Control the lithography equipment to move in the step direction according to the preset step length.

S230. Determine the actual movement distance of the lithography equipment according to the movement of the positioning device.

Wherein, the positioning device includes a grating ruler and a reading head. The reading head of the positioning device moves with the movement of the lithography equipment. Therefore, the reading head of the positioning device can determine the actual distance moved by the lithography equipment.

Illustratively, Figure 11 shows a scanning lithography equipment provided by an embodiment of the present invention. As shown in Figure 11, a grating ruler 630 is provided on both the stage rail 610 and the beam frame 620, and a grating ruler 630 is provided on the lithography equipment 640. There is a reading head 650. The reading head 650 can move with the movement of the lithography equipment 640 to read the grating scale 630, thereby determining the actual movement distance of the lithography equipment.

S240. Determine the step error of one step according to the actual moving distance and the preset step length.

S250: Adjust the spot image based on the step error to compensate for the exposure image error caused by the step error.

Figure 12 is a control device for stepper lithography provided by an embodiment of the present invention. As shown in Figure 12, the device includes:

Position determining device 710 is used to obtain the actual moving distance of the lithography equipment after one step;

The error determination device 720 determines the step error of a step based on the actual movement distance and the preset step length;

The light spot adjustment device 730 adjusts the light spot image based on the step error to compensate for the exposure image error caused by the step error.

The technical solution of this embodiment is to first obtain the actual moving distance of the lithography equipment after one step through the position determining device, then the error determining device determines the step error of one step based on the actual moving distance and the preset step length, and finally the light spot The adjustment device adjusts the spot image based on the step error to compensate for the exposure image error caused by the step error, thereby ensuring the accuracy of the spot image projection position, thereby ensuring that the exposed image on the part to be lithographed will not produce gaps or overlaps. part, to achieve the continuity of the exposed image and improve the accuracy of the exposed image.

Embodiments of the present invention also provide a control device for stepper lithography. The control device for stepper lithography includes: one or more processors; when one or more programs are executed by one or more processors, a Or multiple processors implement the stepper lithography control method in any of the above embodiments.

The stepper lithography control device provided by the embodiment of the present invention can execute the stepper lithography control method provided by any embodiment of the present invention, and has the beneficial effects of the stepper lithography control method, which will not be described again here. .

Embodiments of the present invention also provide a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the stepper lithography control method of any of the above embodiments is implemented.

Through the above description of the implementation, those skilled in the art can clearly understand that the present invention can be implemented with the help of software and necessary general hardware. Of course, it can also be implemented with hardware, but in many cases the former is a better implementation. . Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product in essence or that contributes to the existing technology. The software product for controlling stepper lithography can be stored in a readable storage medium. , such as floppy disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., to make the stepper lithography control device execute the present invention Methods of the above embodiments.

It is worth noting that in the above-mentioned embodiment of the stepper lithography control device, the various modules included are only divided according to functional logic, but are not limited to the above-mentioned divisions, as long as the corresponding functions can be realized; in addition, , the specific names of each functional device are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the present invention.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be used Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent substitutions are made to some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. A control method for stepper lithography, characterized in that it includes: Obtain the actual moving distance of the lithography equipment after one step; Determine the step error of one step according to the actual moving distance and the preset step length; Adjust the spot image based on the step error to compensate for the exposure image error caused by the step error; The adjustment of the spot image based on the step error includes: The step error indicates that when a step is greater than the preset step length, the exposure image is increased by the width of the step error in the step direction, and the step reverse displacement is increased. The distance of the step error in the exposure image is used to compensate for the exposure image error caused by the step error; The step error indicates that when a step is smaller than the preset step length, the exposure image is reduced by the width of the step error in the step reverse direction, and the displacement is reduced in the step direction. The distance of the step error in the exposure image is used to compensate for the exposure image error caused by the step error. 2. The control method of stepper lithography according to claim 1, characterized in that obtaining the actual moving distance of the lithography equipment after one step includes: Control the lithography equipment to move in the step direction according to the preset step length; The actual movement distance of the lithography equipment is determined according to the movement of the positioning device. 3. The control method of stepper lithography according to claim 1, characterized in that, before obtaining the actual moving distance of the lithography equipment after one step, it includes: Set parameters of the spot image projected by the lithography equipment according to the movement accuracy of the lithography equipment; and or The image to be exposed is divided into images according to the parameters of the spot image. 4. The control method of stepper lithography according to claim 3, wherein the parameters of the spot image projected by the lithography equipment include: the projection length of the spot image and the projection width of the spot image; Wherein, the projection length of the spot image is less than or equal to the maximum projection length of the lithography equipment minus 2 times the movement accuracy of the lithography equipment; the projection width of the spot image is equal to the maximum projection of the lithography equipment width. 5. The control method of stepper lithography according to claim 4, wherein the step of dividing the image to be exposed according to the parameters of the spot image includes: Divide the exposure image into multiple strip images based on the projection length of the spot image and the movement accuracy of the lithography equipment, each strip image including a projection area in the middle and compensation areas on both sides; The width of the projection area is equal to the projection length of the spot image, and the width of the compensation area is greater than the movement accuracy of the lithography equipment. 6. The control method of stepper lithography according to claim 5, characterized in that the projection areas of adjacent strips are not overlapped, and the compensation areas of adjacent strips are overlapped with the projection areas of adjacent strips, The total length of adjacent compensation areas is greater than or equal to 2 times the movement accuracy of the lithography equipment, and is less than or equal to 2 times the projection length of the spot image. 7. A control device for stepper lithography, applied to the control method of stepper lithography according to claim 1, characterized in that it includes: A position determination device used to obtain the actual moving distance of the lithography equipment after one step; An error determination device determines the step error of one step according to the actual moving distance and the preset step length; The light spot adjustment device adjusts the light spot image based on the step error to compensate for the exposure image error caused by the step error. 8. A control device for stepper lithography, characterized in that the control device for stepper lithography includes: one or more processors; When the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the stepper lithography control method as described in any one of claims 1-6. 9. A computer-readable storage medium on which a computer program is stored, characterized in that when the program is executed by a processor, the stepper lithography control method according to any one of claims 1-6 is implemented.